. >>> later on, what do you get when santa claus meets a science fiction fantasy? stay tuned for our "world news now" christmas tradition called "st. nick and the space nicks." i've never seen this. i'm very excited. >> you have your mug now and you're going to go through that. so you're officially part of the overnight family. you've been indoctrinated with us now. >> i'm happy to be here. >> merry christmas. always good to have you. but first, it is a white christmas for parts of the country. philadelphia and many cities in the northeast got a few inches of snow, but it won't last long due to a coming meltdown. >> it's part of a system that snarled traffic and delayed airline passengers. as abc's alex perez reports. >> reporter: blankets of snow from central new york to northern california, creating christmas chaos for some parts of the country. >> we're hoping we don't sit on the runway. we did that the last time. >> reporter: in chicago, paula and her three daughters arrived early for their christmas eve flight. they are among the millions taking to the crowded